FIG. 9 shows a conventional ratchet wrench (50) including a rotating unit (60) on one end to rotate the wrench (50) to tighten or loosen a nut or bolt. A teeth ring (61) is formed outside the rotating unit (60), one side of which has a corresponding ratchet unit (70), and the ratchet unit (70) can move in a first receiving space (51) inside the wrench (50). An arc surface (71) is formed on the other surface of the rotating unit (60), and a second receiving space (52) is communicating with the first receiving space (51). A control block (80) is in the second receiving space (52) and a plugging hole (81) is on the control block (80). A spring (82) is disposed on the control block (80) and a cover (83) is formed at the top portion of the spring (82), so the cover (83) can be pushed by the spring (82) to be against the arc surface (71) of the ratchet unit (70). With the control block (80) controlling the cover (83) to push the ratchet unit (70) to different sides of the first receiving space (51), a unidirectional driving effect can be generated.
However, the conventional ratchet wrench structure has some disadvantages: (i) the spring (82) and the cover (83) are disposed between the ratchet unit (70) and the control block (80), and one side of the cover (83) is pushed by the spring (82), and the other side is against the arc surface of the ratchet unit (70). When the wrench (50) is operated to shake the ratchet unit (70) or the control block is operated to switch, one end of the cover (83) moves to the arc surface (71) of the ratchet unit (70), and the other end moves to the plugging hole (81), the cover (83) and spring (82) can be easily deformed or pops out from the plugging hole (81); (ii) the control block (80) is disposed in the second receiving space (52) and secured the control block (80) to restrict the control block (80) to only rotate. Furthermore, the spring (82) is plugging into the plugging hole (81) through the first receiving space (51), and the top portion of the spring (82) covers the cover (83). Since the opening of the first receiving space (51) is facing the rotating unit (60), it is difficult to install the spring (82). Also, the spring (82) and cover (83) are small, they may be missing during the assembly process to further increase the difficulty during the assembly process; and (iii) the spring (82) and the cover (83) are disposed between the ratchet unit (70) and the control block (80), and one end of the cover (83) is pushed by the spring (82), while the other end thereof is pressed against the arc surface (71) of the ratchet unit (70). When the ratchet unit (70) is operated, the cover can push the spring (82), so a space for the ratchet unit (70) can be maintained between the ratchet unit (70) and the control block (80) and the cover (83) and spring (82) will be over-protruding from the plugging hole (81) to adversely affect the positioning of the cover (83) and spring (82). Therefore, there will still be a need for a new and improved ratchet wrench structure to overcome the problems presented above.